Selective actuating mechanism for percussive photoflash lamp array

ABSTRACT

For a photoflash assembly comprising a plurality of percussively-ignitable flashlamps arranged in an array with respectively associated reflectors and preenergized striker springs, a self-energized selective actuating mechanism for sequentially releasing the striker springs to fire respective flashlamps in response to successive indexing. The actuating mechanism includes a coplanar train of intermeshing spur gears having a number of circumferentially spaced projecting ramps. The lamps and striker springs are supported on the end surfaces of shafts upon which the gears are mounted, with the strikers radially projecting over the surrounding gear to lie in the path of travel of the ramps. A spring-loaded, sliding rack gear is enmeshed with one of the spur gears and is position-controlled by a spring-loaded, pivoted arm having a pin engaging a sawtooth slot cam in the rack gear. To flash a lamp, the pivoted arm is raised so that the cam-engaging pin clears a vertical portion of the sawtooth slot and thereby releases the spring-loaded rack gear to rotationally index the gears while the cam-engaging pin rides down a ramp portion of the sawtooth slot. The gear indexing permitted by the pitch of the sawtooth slot causes one of the ramps to release a striker.

United States Patent [1 1 McDonough 1451 Oct. 30, 1973 SELECTIVEACTUATING MECHANISM FOR PERCUSSIVE PHOTOFLASH LAMP ARRAY [75] Inventor:Thomas B. McDonough, Allenwood,

[73] Assignee: GTE Sylvania Incorporated, Danvers, Mass.

22 Filed: Jan. 2, 1973 21 Appl. No.: 320,007

[52] U.S. Cl...; 240/l.3, 95/11 L, 431/93 Germany 240/1 .3

Primary Ex'aminerFred L. Braun AttorneyNorman J. OMalley [57] ABSTRACTFor a photoflash assembly comprising a plurality ofpercussively-ignitable flashlarnps arranged in an array withrespectively associated reflectors and preenergized striker springs, aself-energized selective actuating mechanism for sequentially releasingthe striker springs to tire respective flashlamps in response tosuccessive indexing. The actuating mechanism includes a coplanar trainof intermeshing spur gears having a number of circumferentially spacedprojecting ramps. The lamps and striker springs are supported on the endsurfaces of shafts upon which the gears are mounted, with the strikersradially projecting over the surrounding gear to lie in the path oftravel of the ramps. A spring-loaded, sliding rack gear is enmeshed withone of the spur gears and is position-controlled by a spring-loaded,pivoted arm having-a pin engaging a sawtooth slot cam in the rack gear.To flash a lamp, the pivoted arm is raised so that the cam-engaging pinclears a vertical portion of the sawtooth slot and thereby releases'thespring-loaded rack gear to rotationally index the gears while thecam-engaging pin rides down a ramp portion of the sawtooth slot. Thegear indexing permitted by the pitch of the sawtooth slot causes one ofthe ramps to release a striker.

18 Claims, 7 Drawing Figures S 30 34 :8 &\ 1o. 10 i 32 \se 096 5 Y .zgqa2s 58 '5 ze {*6 34 34 6 '9. i

46 45 46 ,Z.' 3' OJ 34 56 I r7 66 60 78 72 so 4 FEJETFU'UQQJ 9o- 82 ge74 16 SELECTIVE ACTUATING MECHANISM FOR PERCUSSIVE PHOTOFLASH LAMP ARRAYBACKGROUND OF THE INVENTION tability. A currently popular flash lampunit of this type is known generally in the trade as flashcube, aspecific embodiment of which is shown in US. Pat. No. 3,327,105, forexample. The unit comprises a set of four flashlamps, each with its ownreflector, mounted on a base and enclosed within a transparent cover,with I 7 each of the lamp-reflector assemblies facing a respective oneof the four side walls of the cube. A spindle depends from the center ofthe flashcube base for operatively retaining the unit in a complementaryreceiving socket on a camera. In operation, the flashcube issequentially rotated a quarter of a turn at a time, usually in responseto each operation of the film advance mechanism of the camera, tosuccessively place unused lamps in a firing position facing the objectbeing photographed. Each of the flashlamps consists of an hermeticallysealed, light transmitting glass envelope containing a filamentarycombustible material, such as shredded zirconium foil, and a combustionsupporting gas, such as oxygen. In the case of flashcubes employingelectrically ignited lamps, a pair of lead-in wires pass through thelamp envelope to support therein a fila ment in combination withglobules of ignition paste. When the flashcube is in the firingposition, segments of the lead-in wires disposed outside the lampenvelope are securely engaged with electrical contacts in the camerasocket, which in turn are connected by wires and a shutter actuatedswitch to the camera power source, usually a pair of dry cell batteries.When a photographer actuates the shutter release mechanism to snap" apicture, he also, by the same operation, closes the electrical circuitfrom the batteries to the ignition system in the lamp to thereby flashthe lamp. The timing of the ignition of the combustible material in thelamp is synchronized with the exposure of the film by actuation of theshutter release so that efficient utilization of the light from theflashlamp may be obtained.

A not infrequent problem that has been faced by the average amateurphotographer when using a battery operated flash system, however, hasbeen failure of the lamp to fire due to weak batteries and/or dirt orcorrosion on one or more of the. electrical contacts in the system. Toovercome this problem and provide improved flashlamp reliability,percussive-type flashlamps have been developed which may be mechanicallyfired withminating materialon a wire supported in the tube. Operation ofthe percussive flashlamp is initiated by an impact onto the tube tocause deflagration of the fulminating material up through the tube toignite the combustible disposed in the lamp envelope. The percussivetypelamps are also produced in subminiature envelope sizes and are employedin percussive flashcube units having respective preenergized strikersprings associated with each lamp, as described in US. Pat. No.3,597,604. The percussive flashcube is indexed into firing positionsimilarly to the electrical flashcube; however, the flashlamp to be usedis fired by the action of a member, associated with the camera shuttermechanism, moving up through the flashcube base to release therespective preenergized striker spring, whereby it sharply impactsagainst the primer tube of the lamp.

Another development in the field of multilamp flash units for providingadditional convenience and flexibility is the provision of a linear orplanar array of flashlamps. In such an arrangement, a plurality of lampsface in the direction of the object being photographed whereby it ispossible to rapidly switch from one lamp to another or to flash morethan one lamp at a time if additional light'is required. Examples ofpreviously described flashlamp arrays are provided by the following US.Pat. Nos.: 3,267,272; 3,430,545; 3,438,315; 3,454,756; 3,458,270;3,473,880; 3,500,732; 3,544,251; 3,545,904; 3,443,875; 3,552,996;3,562,508; 3,598,984; 3,598,985; 3,608,451; and 3,614,112.

All of these patents describe electrically energized flash systems withthe sequence of lamp flashing being controlled by various electricalswitching means including: manually controlled spring slide contacts; arotary switch; thermally or chemically reactive switches placed inthermal proximity to the flashlamps; a switch within each lamp envelopewhich closes in response to firing to prepare the next lamp-in sequence;a voltage surge across the lamps causes ignition of only the lamp havingthe lowest voltage break down characteristics; bimetallic switches; ameltable junction within each lamp envelope; a solid state switchingcircuits. Although providing a number of advantages, the electricalarrays are still prone to the reliability problems associated with anelectrical flash system, namely, ignition failures due to weak batteriesand/or corroded electrical contacts.

Another disadvantage of electrical arrays is the rela tive difficulty ofmaintaining the proper lamp firing sequence in the event the array isremoved from a camera and subsequently replaced. To overcome thisproblem, the prior art, as indicated above, employs special typeflashlamps or relatively complex memory circuits or switches in thecamera. Such approaches are generally considered undesirable with regardto both cost and reliability.

To overcome the above described disadvantages of electrical arrays,. acopending application Ser. No. 260,286, filed June 6, 1972 and assignedto the present assignee, describes a planar photoflash lamp arrayincluding a plurality of percussively-ignitable flashlamps arranged inparallel rows on a support member, along with respectively associatedreflectors and preenergized striker springs. The array further includesa selective actuating mechanism comprising a coplanar train ofintermeshing spur gears having a number of circumferentially spacedprojecting ramps. The gears are supported on shafts having end surfacesupon which the percussive lamps and associated strikers are mounted, andthe strikers are radially disposed over the gear and lie in the path oftravel of the projecting ramps. Upon the gear train is indexed by acamera energized actuat ing member which successively pushes againstpins on the periphery of one of the gears.

SUMMARY OF THE INVENTION Operation of the percussive array described inthe aforementioned copending .application is dependent upon adequatestored energy in the, camera mechanism for rotationally indexing thegear train. In many applications, however, it is desirable tosubstantially reduce or virtually eliminate the power required from thecamera mechanism to cause indexing of the movable mem- 1 her in thepercussive array.

Accordingly, it is an object of the present invention to provide aself-energized actuating mechanism for a percussive photoflash lamparray.

A further object of the invention is to provide a percam followerinhibits indexing of the spring-loaded movable member and locks theposition of the gear train. Upon actuation, a predetermined change inthe position of the cam follower momentarily releases the.

spring-loaded movable member to permit indexing of the gear train untilthe cam follower reaches another quiescent positionon the cam surface.The gear train is then operative. upon successive indexing tosequentially release the preenergized strikers in the array by means ofprojecting means on the gears to thereby fire respective flashlamps ofthe array.

In one embodiment, the secondary movable member comprises aspring-loaded rack gear having a sawtooth slot cam in one of its sides.The slot cam is engaged by a pinprojecting from a pivoted arm which maybe actuated to control indexing of the rack gear and the springreleasinggear train engaged therewith.

BRIEF DESCRIPTION OF THE DRAWINGS This invention will be more fullydescribed hereinafter in conjunction with the accompanying drawings inwhich:

FIG. 1 is a perspective view of the exterior of a' multilamp photoflashassembly including features of the invention;

FIG. 2 is a plan view on an enlarged scale of the rear wall of theflash. assembly of FIG. 1 with a selfenergized gear actuating mechanismaccording to the invention and several striker spring members shown infull and the several flashlamps associated therewith shown in phantom;the view also includes a sectional representation of the base member toshow the aperture therethrough;

FIG. 3 is a side view onan enlarged scale of the flash assembly of FIG.1 with the side wall removed;

FIG. 4 is a fragmentary view of an enlarged scale of a singlelamp-firing spring assembly;

4 FIG. 5 is an enlarged-scale detail view of the springloadedrack gearand pivoted arm cam control arrangement in the actuating mechanism ofFIG. 2;

FIG. 6 is a fragmentary top view in enlarged detail of the rack gear andpivoted arm of FIGS. 2 and 5; and,

FIG. 7 is an enlarged fragmentary sectional view on line 77 of FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENT In tlie specific embodimentillustrated in FIGS. 1-3, the photoflash assembly comprises a group ofeight axially disposed flashlamps 10 and associated coaxial reflectors12 arranged in a compact planar array comprising two stacked rows offour lamps each. The array is housed in a box-like container 14comprising a substantially planar base member 16, a substantially planarsupport member 18 secured to the rear of base 16 and disposedsubstantially normal thereto, a pair of side walls 20 and 22, and a topwall 24. Members 16-24 may comprise a unitary structure of moldedplastic, or support member 18 may be separately attached. Enclosure iscompleted by a sheet of transparent plastic material 26 attached as afront wall to container 14 and disposed over the light emitting side ofthe array.

Referring to FIGS. 2 and 3, the flashlamps 10 are mounted on one side ofthe support member 18 with the longitudinal axes of the lamps disposednormal thereto. Also mounted on support member 18 are eight preenergizedstriker springs 28 each positioned in operative relationship withrespect to one of the lamps. As will be described in detail hereinafter,the striker springs are individually releasable to fire the respectivelyassociated lamps.

As best shown in FIG. 2, the selective actuating mechanism according tothe invention comprises a coplanar train of two intermeshing spur gears30 and 32 each having a number of circumferentially spaced projectingramps 34. The gears are rotatably mounted on a pair of shafts 36 and 38fixedly secured at one end to the support member 18. Preferably theshafts comprise integral molded portions of the support member 18. Thefree-end of each shaft has a substantially planar surface parallel tothe plane of the gear mounted thereon, and the gear train is arrangedparallel to support member 18. To enable the desired coaction betweenthe gear mechanism and the lamp firing springs,

a cluster of four lamps 10 and four striker springs 28 are symmetricallydisposed on the end surface of each shaft so as to provide an overalleight lamp array consisting of two parallel rows of four equally spacedlamps.

Referring to FIGS. 1 and 3, each concave reflector 12 is disposedcoaxially about its associated tubular shaped lamp 10,- with allreflectors oriented to face in one direction away from the lamp mountingsurface. Each reflector is essentially parabolic but modified by theprovision of four flats 39 along the sides thereof. Adjacent flats ofadjacent reflectors abut one another to define a compact planar array ofreflectors. As may be noted from FIGS. 2 and 3 the hairpin torsionalsections of the group of four springs 28 on each shaft are clustered inthe central space provided behind each square group of four reflectors.

The array of eight reflectors 12 may comprise a single preformed sheet40 of plastic material having a light reflective coating; for example,the inwardly dished reflector surfaces 12 may be provided by vacuumforming. Toward the vertex of each reflector is provided a coaxialaperture 41 of suitable shape for fitting about the tubular flashlamp10. If the radiation from a flashed lamp proves to be a problem bycausing sympathetic application.

I As shown particularly in FIG. 4, each lamp comprises an hermeticallysealed light-transmitting envelope 42 of tubular shape having a primer44 depending therefrom. A filling of combustible foil 43, such aszirconium, and a combustion-supporting gas, such as oxygen, are disposedin the envelope. The primer comprises a metal tube 44 coaxiallyprojecting from the envelope and within which a wire anvil and a chargeof fulminating material are disposed. Each lamp is supported on thesupport. member 18 to project normal therefrom and thusaxially parallelto base 16, by means of a respective bore 46 into which the primer tube44 is inserted. That is, there are four bores 46 in each of the shaftend surfaces, as shown in FIG. 2.

Each preenergized striker spring comprises a folded torsion devicetypically formed from 0.021 inch music wire about 2.5 inches long. Thewire is shaped to form a hairpin torsional section having segments 47and 48 .joined by a bight 50. The end portion of segment 47 is shaped todefine a stationary supporting foot 52, the tip of which is shapedtodefme a catch 54. Portions of foot 52 and catch 54 are hidden in FIG.4. The end portion of segment 48 is shaped to define a striker 56, whichwhen the spring is preenergized, or cocked, as shown, crosses over thesupporting foot 52 and is restrained by the catch 54. The stationarysupporting foot is seated in an elongated slot formed in the circularend surface of the gear shafton or near a diagonal thereof, the slotbeing sufficiently shallow to permit catch 54 to project from the endsurface of the shaft.

Initially the striker 56 may be formed at an angle of about 90 to thestationary supporting foot 52, although the angle through which thestriker is rotated to positionit behind catch 54, as shown, may be ofany value that does not cause over stressing of the wire. A center post58 on the end surface of each gear shaft provides a suitable bearingsurface for the heel of the strikerduring cocking, and it also aids inpreventing accidental displacement of the spring 28 sufficient to freethe striker from the catch some time after cocking and before firing isintended.

Selective displacement of each cocked striker 56, to

. release it from catch 54 and thus permit it to strike the respectiveprimer tube 44 and fire the associated lamp 10, is effected byrotationaly indexing of the gear train. More specifically, asillustrated in FIG. 2, the firing springs 28 on each shaft are arrangedwith the strikers 56 disposed in a symmetrically radial pattern andprojecting beyond the periphery of the circular end surface to overlie aportion of the gear mounted on that shaft. In particular, the free endsof the strikers 56 are disposed to lie in,the path of travel of theramps 34, which project from each gear. Hence, upon rotationallyindexing the gear train, the striker adjacent to an oncoming ramp 34, asshown in FIG. 4, is pushed upwardly by the ramp a distance sufficient toclear the top of the catch 54.- The striker then swings clockwise, asindicated by the arrow, and hits and indents the impact sensitive primertube 44 at a high velocity to cause deflagration of the fulminatingmaterial located therein and thus ignite the combustible foil 43.

Rotational indexing is initiated by external means, but the externalenergy requirement is minimized, in accordance with the invention, byself-energizing the photo-flash assembly actuating mechanism in thefollowing manner. As illustrated in FIGS. 2 and 3, and in the detailviews of FIGS. 7, the mechanism further includes a rack gear 60 slidablymounted in a channel 62 (FIGS. 6 and 7) in either base 16 or aprojecting portion of support member 118 so as to engage spur gear 30 byintermeshing of the respective teeth thereof.

The rack' gear 60 may be held in the channel by means of flanges 63(FIG. 7) which project at right angles from the bottom of the rack andengage grooves 65 along the lower portions of the sidewalls of channel62. A compression coil spring 64 (FIG. 7, and dashed lines in FIGS. 2and 5) is inserted part way through the center of rack gear 60 andconnected (e.g. by spring pressure) between an internal portion of therack gear and the left end of support member 18 (or wall 20) to providesufficient spring loading for urging the rack gear to translate alongchannel 62 from left to right. Accordingly, spring 64 provides theenergy for rotating the gear train 30, 32 pursuant to translation ofrack gear 60.

Indexing of the rack gear, and consequently the spur gear train, iscontrolled by a spring loaded cam follower which engages a cam surfacecomprising a sawtooth slot 66 located on one side of the rack gear. Morespecifically, the cam follower comprises a pin 68 attached to the leftend of a pivoted arm 70 monted on base 16 or a projecting portion ofsupport member 18. For example, the right end of arm 70 may be securedby a pivot pin 72 to an upstanding support 74.

Each sawtooth of the slot cam 66 has a vertical portion 76 and a rampportion 78 (FIG. 5). Normally, the pin 68 engaging slot 66 assumes aquiescent position at the bottom of vertical portion 76, as shown inFIG. 5. In this quiescent position, pin 68 inhibits indexing of the rackgear and thereby locks the position of the spur gears 30 and 32.Preferably, the pivoted arm 70 is loaded by a spring 30 to urge pin 68toward the bottom of the vertical slot portion 76, thereby insuring thatthe gear train is not unintentionally released by mechanically inducedshock during handling and shipping.

In the embodiment illustrated, the pivoted arm contains a flat tab 82which is rendered accessible to external actuating means through anaperture 84 provided in base member 16. For example, gear indexing maybe effected by a suitable actuating member 86 moving up through aperture84 to engage and push against the tab 82 of the spring loaded arm 70.The upward movement of member 86 causes pin 68 to traverse the verticalportion 76 until it clears the top of the vertical face of the slot camand is thereby placed in movable engagement with the ramp portion 78.This action releases the rack gear 60 to permit the loading spring 64 topush the sliding rack to the right and thereby rotate gear 30counterclockwise, which in turn rotates gear 32'clockwise. The movementof the rack 60 forces pin 68 to travel down the ramp portion 78 of theslot cam until it contacts the next vertical face and thereby stops thesliding rack and prevents further rack travel. Hence the gear rotationis a momentary indexing movement, as the angular displacement isterminated when the travel of pin 68 reaches the next quiescent positionon the slot cam at the bottom of a vertical portion 76. The angulardisplacement resulting from the aforementioned operation is determinedby the pitch of the sawtooth slot and, in the illustrated embodiment, isoperative to cause one lamp to be fired. In a typical application,actuating member 86 may be part of a camera mechanism designed to enablethe photographer to flash a lamp in synchronization with the tripping ofthe camera shutter to take a picture. The camera machanism should bedesigned so that it senses downward travel of the pin 68 and arm 70assembly and thereupon disconnects the camera source of motive power topermit the spring loaded arm and pin to lock the position of the geartrain and prevent release of a second spring.

After the last lamp has been flashed, pin 68 slides into a straight slot88, whereupon tab 82 is in a high position so that the camera can sensethat the array is expended.

In the present flash unit, eight lamps are available to be sequentiallyflashed in response to successive indexing of the gear train by thepivoted arm and camcontrolled rack. Thus, for example, eight rapid flashexposures may be taken with a camera, without the need for moving thelamps or rotating the unit. The sequence of releasing the strikers inresponse to indexing is programmed by the number and circumferentiallocation of the ramps 34 on each gear. That is, the ramps 34 arearranged so that for a selected increment x of rotational displacement,the gear travel will cause a first ramp in the train to release astriker and a second ramp in the train to be moved to a positionadjacent another preenergized striker 56, as shown in FIG. 4. Thispattern of ramp positioning then continues for all successive 1:increments of rotation until all springs have been released. Typically,each indexing cycle will produce an x increment of gear rotation toprovide a single lamp ignition.

As described above, the new position of the gear train is retained aftereach indexing cycle by means of the spring loaded arm 70, which returnspin 68 to engage the next vertical cam slot on rack gear- 60. Hence, byvirtue of the mechanical firing system, the rampprogramming, and thecam-controlled rack, the present photoflash assembly provides aself-contained memory function, whereby the next unused lamp in theflash sequence will always be ready for immediate triggering,

even through the unit may have been removed from the camera andsubsequently replaced. This is a significant advantage as compared toelectrical arrays.

Most importantly, however, substantially all of the power required torotate the spur gears 30, 32 and release all eight springs is providedby the rack loading spring 64. The only power required from the camerawould be the small amount required to push the pivoted arm 70upward'untilfpin 68 clears the vertical stop face. Hence, aself-energized, percussive flashlamp array is provided whichsubstantially reduces the camera power requirements for flash actuation.

In one embodiment of this invention, as illustrated in FIG. 2, a pair ofspur gears 30 and 32 each having 32 teeth and a diameter of one inch aremounted on a sup port member 18. Two ramps 34 are provided on each gearthereby requiring 180 total rotation to release the eight strikersprings. Each of the ramps 34 comprises a projection sloped on twoopposite sides so that the same standard gear design can be used forboth clockwise and counterclockwise gear rotation. The gears areretained on shafts 36 and 38 by the overlying strikers 56; hence, theramps 34 are located radially outward from the inside edge of each gearto provide clearance for striker overhang after the spring is releasedso that the gears will continue to be held in position but free torotate. The center to center circumferential spacing of the ramps is 135(12 teeth), and the starting position of the gears is as shown in FIG.2.

The bottom of the base 16 may be provided with suitable means formounting the photoflash assembly on apparatus such as a camera. Forexample, as shown in FIGS 2 and 3, a mounting post 90 may be providedwhich is shaped to mate with the socket ona camera of the type generallyavailable for use with percussive flashcubes, such as that described inUS. Pat. 3,602,618, for example. In such cases, either the camera wouldbe modified to render the socket nonrotating, or the post 90 would beallowed to rotate while the base remains stationary. The latter designapproach would make the array adaptable for use on a camera which isalso usable with rotating fiashcubes. in addition, the camera would bemodified to remove the upward sensing portion of the operation (fordetecting released strikers), or spring 80 would be made sufficientlystrong to prevent arm from releasing the rack during the upward sensingmovement of actuating member 86. Also, as mentioned hereinbefore, theCamera should be modified to sense downward travel of the pin 68 and arm70 assembly, and in response thereto, retract member 86 toprevent'unintentional spring release.

Although the invention has been described with respect to specificembodiments, it will be appreciated that modifications and changes maybe made by those skilled in the art without departing from the truespirit and scope of the invention. For example, the number of lamps inthe array may be varied, with a corresponding variation in the number ofgears. Also, the number and spacing of the ramps 34 mayvary, The gearscan be arranged in various ways, yielding vertical, square, rectangular,T-, or L-shaped gear train configurations. Means other than ramps may beemployed for selectively releasing the strikers. The slot cam may belocated on the bottom or opposite side of the rack. The lever arm andpin may be located differently. An extension coil spring connectedbetween the rack and the I right end of the support member may be usedfor loading the sliding rack gear in lieu of the described compressionspring. Further the rack may engage pins rather than gear teeth totransmit linear to rotational motion.

What I claim is:

l. A self-energized selective actuating mechanism for a photoflash lamparray; said array including a support member, a plurality ofpercussively-ignitable flashlamps mountedon said support member, and aplurality of preenergized strikers mounted on said support memberandreleasable to tire said flashlamps; the selective actuating mechanismcomprising:

a first movable member;

means supporting said first movable member in operative alignment withrespect to said strikers;

means projecting from said first movable member and adapted forselectively releasing said preenergized strikers;

a second movable member engaged with said first movable member andhaving a cam surface thereon;

means for spring loading said second movable member sufficiently tocause indexing thereof and thereby indexing of said first movable memberengaged thereto; and,

a cam follower engaging the cam suface on said second movable member,said cam surface being shaped whereby the quiescent position of said camfollower inhibits indexing of said second movable member and apredetermined change in position of said cam follower momentarilyreleases said springloaded second movable member to permit indexing ofsaid second and first movable members until said cam follower reachesanother quiescent position on said cam surface;

said first movable member being operative upon successive indexing tosequentially release said strikers by means of said projecting means tofire respective flashlamps of said array.

2. The mechanism of claim 1 further including means for spring loadingsaid cam follower.

3. The mechanism of claim 1 wherein said cam follower comprises a pinattached to a pivoted arm supported in operative relationship to saidsecond movable member and operative upon actuation to cause release ofsaid spring-loaded second movablemember to permit indexing of saidsecond and first movable members by an amount determined by the shape ofsaid cam surface engaged by said pin.

4. The mechanism of claim 3 further including means for spring loadingsaid pivoted arm.

5. The mechanism of claim 1 wherein said cam surface comprises asawtooth slot in said second mova'ble member, said slot having avertical portion and a ramp portion, the quiescent position of said camfollower being in the vertical portion of said sawtooth slot, and saidsecond movable member being released for indexing when the position ofsaid cam follower is changed to permit it to movably engage the rampportion of said sawtooth slot.

6. The mechanism of claim 5 wherein said cam follower comprises a pinattached to a spring-loaded, pivoted arm supported in operativerelationship to said second movable member and operative upon actuationto cause said pin to traverse the vertical portion of said sawtooth slotinto movable engagement with the ramp portion of said slot, therebyreleasing said springloaded second movable member to permit indexing ofsaid second and first movable members by an amount determined by thepitch of said sawtooth slot.

7. The mechanism of claim 1 wherein said first movable member comprisesa spur gear, said supporting means comprises a portion of said supportmember shaped to provide a stationary shaft upon which said spur gear isrotatably mounted, said shaft having a free end with a substantiallyplanar surface parallel to the plane of said spur gear, said flashlampsand strikers are mounted on said planar surface at the free end of saidshaft with said preenergized strikers being disposed radially thereon,and said second movable member comprises a rack gear slidably mounted inoperative relationship to said spur gear.

8. The mechanism of claim 7 wherein said spring loading means comprisesa compression coil spring connected between said support member and saidslidable rack gear for urging said rack gear into translation.

9. The mechanism of claim 7 wherein said rack gear is engaged with saidspur gear by intermeshing of the respective teeth thereof.

10. The mechanism of claim 7 wherein said cam surface comprises asawtooth slot in a side of said rack gear, said slot having a verticalportion and a ramp portion, and said cam follower comprises a pinattached to a pivoted arm supported in operative relationship to saidrack gear, the quiescent position of said pin being in the verticalportion of said sawtooth slot, and said pivoted arm being operative uponactuation to cause said-pin to traverse the vertical portion of saidsawtooth slot into movable engagement with the ramp portion of saidslot, whereby said spring-loaded rack gear is released to permittranslation thereof, and consequently rotational indexing of said spurgear, by an amount determined by the pitch of said sawtooth slot.

11. The mechanism of claim 10 further including means for spring loadingsaid pivoted arm.

12. A photoflash assembly comprising, in combination:

a'substantially planar support member;

a plurality of shafts fixedly secured at one end to said support member;

a coplanar train of intermeshing spur gears rotatably mounted on saidshafts, each of said gears on a respective one of said shafts, with saidgear train lying in a plane parallel to said support member;

the free end of each of said shafts having a substantially planarsurface parallel to the plane of the gear mounted thereon and the planeof said support member;

a plurality of percussively-ignitable flashlamps mounted on the planarsurface of each of said shafts with the longitudinal axes of said lampsdisposed normal to said planar surface;

a plurality of preenergized strikers radially mounted on the planarsurface of each of said shafts and individually releasable to fire arespective one of said flashlamps;

means projecting from said gears and adapted for selectively releasingsaid preenergized strikers;

a movable member mounted on said support member and engaged with one ofsaid gears, said movable member having a cam surface thereon;

means for spring loading said movable member sufficiently to causeindexing thereof and thereby indexing of said gear train; and,

a cam follower connected to said support member and engaging the camsurface of said movable member, said cam surface being shaped wherebythe quiescent position of said cam follower inhibits indexing of saidmovable member and a predetermined change in position of said camfollower momentarily releases said spring-loaded movable member topermit indexing of said movable member and said gear train until saidcam follower reaches another quiescent position on said cam surface;

said gear train being operative in response to successive indexing tosequentially release said strikers by means of said projecting means tofire respective flashlamps of said array.

13. The mechanism of claim 12 wherein said movable member comprises arack gear slidably mounted on said support member, and said cam surfacecomprises a sawtooth slot in a side of said rack gear, said slot havinga vertical portion and a ramp portion, the quiescent portion of said camfollower being in thevertical portion of said sawtooth slot, and saidslidable rack gear being released for indexing when the position of saidcam follower is changed to permit it to movably engage the ramp portionof said sawtooth slot.

lower comprises a pin attached to a pivoted arm mounted on said supportmember, said pivoted arm being accessible to be actuated for causingsaid pin to traverse the vertical portion of said sawtooth slot intomovable engagement with the ramp portion of said slot,

whereby said spring-loaded rack gear is released to permit translationthereof, and consequently indexing of said gear train, by an amountdetermined by the pitch of said sawtooth slot.

17. The mechanism of claim 16 further including means for spring loadingsaid pivoted arm.

18. The assembly of claim 16 wherein the radially mounted strikers ofeach shaft project beyond the periphery of the planar surface thereof tooverlie a portion of the spur gear mounted thereon, and said meansprojecting from said spur gears comprises oneor more ramps on each ofsaid spur gears, said sequence of releasing said strikers beingprogrammed by the number and circumferential location of said ramps oneach gear.

1. A self-energized selective actuating mechanism for a photoflash lamparray; said array including a support member, a plurality ofpercussively-ignitable flashlamps mounted on said support member, and aplurality of preenergized strikers mounted on said support member andreleasable to fire said flashlamps; the selective actuating mechanismcomprising: a first movable member; means supporting said first movablemember in operative alignment with respect to said strikers; meansprojecting from said first movable member and adapted for selectivelyreleasing said preenergized strikers; a second movable member engagedwith said first movable member and having a cam surface thereon; meansfor spring loading said second movable member sufficiently to causeindexing thereof and thereby indexing of said first movable memberengaged thereto; and, a cam follower engaging the cam suface on saidsecond movable member, said cam surface being shaped whereby thequiescent position of said cam follower inhibits indexing of said secondmovable member and a predetermined change in position of said camfollower momentarily releases said spring-loaded second movable memberto permit indexing of said second and first movable members until saidcam follower reaches another quiescent position on said cam surface;said first movable member being operative upon successive indexing tosequentially release said strikers by means of said projecting means tofire respective flashlamps of said array.
 2. The mechanism of claim 1further including means for spring loading said cam follower.
 3. Themechanism of claim 1 wherein said cam follower comprises a pin attachedto a pivoted arm supported in operative relationship to said secondmovable member and operative upon actuation to cause release of saidspring-loaded second movable member to permit indexing of said secondand first movable members by an amount determined by the shape of saidcam surface engaged by said pin.
 4. The mechanism of claim 3 furtherincluding means for spring loading said pivoted arm.
 5. The mechanism ofclaim 1 wherein said cam surface comprises a sawtooth slot in saidsecond movable member, said slot having a vertical portion and a rampportion, the quiescent position of said cam follower being in thevertical portion of said sawtooth slot, and said second movable memberbeing released for indexing when the position of said cam follower ischanged to permit it to movably engage the ramp portion of said sawtoothslot.
 6. The mechanism of claim 5 wherein said cam follower comprises apin attached to a spring-loaded, pivoted arm supported in operativerelationship to said second movable member and operative upon actuationto cause said pin to traverse the vertical portion of said sawtooth slotinto movable engagement with the ramp portion of said slot, therebyreleasing said spring-loaded second movable member to permit indexing ofsaid second and first movable members by an amount determined by thepitch of said sawtooth slot.
 7. The mechanism of claim 1 wherein saidfirst movable member comprises a spur gear, said supporting meanscomprises a portion of said support member shaped to provide astationary shaft upon which said spur gear is rotatably mounted, saidshaft having a free end with a substantially planar surface parallel tothe plane of said spur gear, said flashlamps and strikers are mounted onsaid planar surface at the free end of said shaft with said preenergizedstrikers being disposed radially thereon, and said second movable membercomprises a rack gear slidably mounted in operative relationship to saidspur gear.
 8. The mechanism of claim 7 wherein said spring loading meanscomprises a compression coil spring connected between said supportmember and said slidable rack gear for urging said rack gear intotranslation.
 9. The mechanism of claim 7 wherein said rack gear isengaged with said spur gear by intermeshing of the respective teeththereof.
 10. The mechanism of claim 7 wherein said cam surface comprisesa sawtooth slot in a side of said rack gear, said slot having a verticalportion and a ramp portion, and said cam follower comprises a pinattached to a pivoted arm supported in operative relationship to saidrack gear, the quiescent position of said pin being in the verticalportion of said sawtooth slot, and said pivoted arm being operative uponactuation to cause said pin to traverse the vertical portion of saidsawtooth slot into movable engagement with the ramp portion of saidslot, whereby said spring-loaded rack gear is released to permittranslation thereof, and consequently rotational indexing of said spurgear, by an amount determined by the pitch of said sawtooth slot. 11.The mechanism of claim 10 further including means for spring loadingsaid pivoted arm.
 12. A photoflash assembly comprising, in combination:a substantially planar support member; a plurality of shafts fixedlysecured at one end to said support member; a coplanar train ofintermeshing spur gears rotatably mounted on said shafts, each of saidgears on a respective one of said shafts, with said gear train lying ina plane parallel to said support member; the free end of each of saidshafts having a substantially planar surface parallel to the plane ofthe gear mounted thereon and the plane of said support member; aplurality of percussively-ignitable flashlamps mounted on the planarsurface of each of said shafts with the longitudinal axes of said lampsdisposed normal to said planar surface; a plurality of preenergizedstrikers radially mounted on the planar surface of each of said shaftsand individually releasable to fire a respective one of said flashlamps;means projecting from said gears and adapted for selectively releasingsaid preenergized strikers; a movable member mounted on said supportmember and engaged with one of said gears, said movable member having acam surface thereon; means for spring loading said movable membersufficiently to cause indexing thereof and thereby indexing of said geartrain; and, a cam follower connected to said support member and engagingthe cam surface of said movable member, said cam surface being shapedwhereby the quiescent position of said cam follower inhibits indexing ofsaid movable member and a predetermined change in position of said camfollower momentarily releases said spring-loaded movable member topermit indexing of said movable member and said gear train until saidcam follower reaches another quiescent position on said cam surface;said gear train being operative in response to successive indexing tosequentially release said strikers by means of said projecting means tofire respective flashlamps of said array.
 13. The mechanism of claim 12wherein said movable member comprises a rack gear slidably mounted onsaid support member, and said cam surface comprises a sawtooth slot in aside of said rack gear, said slot having a vertical portion and a rampportion, the quiescenT portion of said cam follower being in thevertical portion of said sawtooth slot, and said slidable rack gearbeing released for indexing when the position of said cam follower ischanged to permit it to movably engage the ramp portion of said sawtoothslot.
 14. The mechanism of claim 13 wherein said spring loading meanscomprises a compression coil spring connected between said supportmember and said slidable rack gear for urging said rack gear intotranslation.
 15. The mechanism of claim 13 wherein said rack gear isengaged with one of said spur gears by intermeshing of the respectiveteeth thereof.
 16. The mechanism of claim 13 wherein said cam followercomprises a pin attached to a pivoted arm mounted on said supportmember, said pivoted arm being accessible to be actuated for causingsaid pin to traverse the vertical portion of said sawtooth slot intomovable engagement with the ramp portion of said slot, whereby saidspring-loaded rack gear is released to permit translation thereof, andconsequently indexing of said gear train, by an amount determined by thepitch of said sawtooth slot.
 17. The mechanism of claim 16 furtherincluding means for spring loading said pivoted arm.
 18. The assembly ofclaim 16 wherein the radially mounted strikers of each shaft projectbeyond the periphery of the planar surface thereof to overlie a portionof the spur gear mounted thereon, and said means projecting from saidspur gears comprises one or more ramps on each of said spur gears, saidsequence of releasing said strikers being programmed by the number andcircumferential location of said ramps on each gear.